How do I cite an Apostolic Exhortation in APA style (in text and in a reference list)?
If you accessed the document from a website, (the Vatican website in English is a good source for Papal documents http://w2.vatican.va/content/vatican/en.html) use the APA Referencing Guide instructions and examples for Web Resources.
Specifically, follow the example at the bottom of the page for PDF found on a website, or if the version you accessed was not a PDF but rather a webpage, follow the example at the top of the Web Resources page. The in-text reference will be simply author, date, e.g. (Francis, 2013).